diff --git a/sys/sys/abi_compat.h b/sys/sys/abi_compat.h
index 1753d8dd25c..69fb349edc7 100644
--- a/sys/sys/abi_compat.h
+++ b/sys/sys/abi_compat.h
@@ -4,6 +4,11 @@
  * Copyright (c) 2001 Doug Rabson
  * All rights reserved.
  *
+ * Copyright 2026 The FreeBSD Foundation
+ *
+ * Portions of this software were developed by Konstantin Belousov
+ * under sponsorship from the FreeBSD Foundation.
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met: